This invention relates to an ingenious improvement in gear systems for power transmission, and is characterized by remarkable simplicity and utility.
In power transmission by means of gear systems there are instances in which the flow of power through the system takes place partly through meshing between adjoining gears and partly through rotation of gears coaxially by each other.
Examples of such gear systems are found in advanced types of machines for automatically developing photographic films, x-ray films and the like. Such machines typically include several compartments through which the films to be processed are successively transported. In these compartments there are performed the various processing operations, including developing, fixing, washing, drying, etc. Especially in advanced, highspeed models of such machines, long, rack-mounted strings of transport rollers are positioned in these compartments to accomplish the transporting of the films through the machine.
There are stringent requirements on the operation of these roller strings. They must be capable of being driven from one end, with a minimum of input power, and they must rotate very smoothly, uniformly, and free from abrupt or jerking movements which could damage the films being processed.
Gear systems capable of being used for such roller racks in a manner which satisfies all of these stringent requirements are taught in our prior patents and patent applications including particularly those listed above.
These gear systems are characterized by the fact that the power flow through the system takes place in two distinctly different ways. Part of this power flow takes place through meshing of consecutive gears. Other parts take place through coaxial connection of one gear with another.
In particular, the transport racks characterizing our prior inventions generally utilize a train of power gears, along which the main flow of power for the rack is transmitted through meshing of consecutive gears in the train (including intermediate reversing gears if appropriate). From different ones of this train of power gears there are then tapped-off fractions of this main flow of power. These tapped-off power fractions are utilized to drive clusters of gears which in turn rotate the individual transport rollers.
The tapping-off of the desired fractions of the main power flow is accomplished by utlizing, at each tap-off point, a cluster drive gear which is smaller in pitch diameter than the corresponding power gear, and which is rotated by that power gear not through meshing, but rather through a coaxial connection.
As is fully set forth in our prior patents and patent applications, film processing machines featuring such a system are remarkably superior to other types.